If you're upgrading to Exchange 2013, the changes to roles, increased memory, CPU and storage requirements might...
leave you reeling. And when you consider the extra server components you need if you want to take advantage of every new feature in Exchange 2013, it could be off-putting. To help ease the stress and help you decide if you need it, we'll break down what Office Web Apps Server 2013 is.
Prior to Exchange 2007, if you wanted to view Microsoft Office format attachments from within Outlook Web App (or Outlook Web Access, as it was known back then), you would need a copy of Office installed on the computer that is reading the email. Not only would you need Office installed, but you'd also have to download a copy of the attachment before you could read it. Exchange 2007 brought the ability to view the attached word document in the Web browser, all of which was rendered on the Exchange Server on behalf of the end user.
Oracle Outside In is the underlying technology that supports the WebReady document viewer built into Exchange 2007, 2010 and 2013. Oracle Outside In is a third-party tool for Exchange that renders Office documents.
Understanding the Office Web Apps Server 2013 role
One of the server products included with Office 2010 was an addition called Office Web Apps Server. Built to compete with Google Apps' online editors, Office Web Apps Server hooked into SharePoint 2010 and Microsoft's SkyDrive service to allow end users to edit Office documents within a Web browser.
Microsoft included Office Web Apps Server 2013 in its suite of Office Server 2013 products (including Exchange, Lync and SharePoint) as well as Office 365 and the latest incarnation of SkyDrive. This brings a number of improvements, including easier installation and broad support across the key Office servers. As well as being useful to SharePoint, Office Web Apps Server plugs into Lync and Exchange to provide Lync Server the facilities to render PowerPoint presentations during conference calls. It also can be used within Exchange as the recommended way to view Office documents within Outlook Web Apps.
If you are deploying Exchange, Lync and SharePoint 2013, it's normal to aim for using a single Office Web Apps Server farm or cluster of servers that provide appropriate resources to render documents and high availability. The single farm can be connected to all three Office Server products and used as a single resource, rendering Office documents on demand.
Benefits of installing Office Web Apps Server 2013
Deploying the Office Web Apps Server can be a difficult pill to swallow for many organizations. Smaller organizations replacing one or two Exchange servers as part of an upgrade typically don't want another server, especially as Office Web Apps Server requires the same resources as a basic SharePoint 2013 installation. Larger organizations with different groups managing Exchange, SharePoint and Lync might also fall afoul of administrative boundaries and find they need multiple Office Web Apps Server farms to ensure different groups can independently update and patch their servers.
All isn't lost if you don't want to implement Office Web Apps Server 2013 as part of your Exchange implementation, but you need to seriously consider the pros and cons of the option you choose. WebReady document viewing is still part of Exchange 2013 and can be enabled after performing a standard server installation. It provides no new features above those available in Exchange 2010 and 2007, but does provide simple Office document viewing.
There is, however, a downside that may make you think twice about using the built-in WebReady document viewing. The underlying technology, Oracle Outside In, has had a large number of security vulnerabilities, many of which have resulted in Exchange Server requiring security patches. And these have affected older versions as well as newer versions of Exchange. Technologies such as Microsoft's EMET will help mitigate underlying flaws, as will pre-authentication on your perimeter network, using, for example, Web Application Proxy.
If you're trying to choose between Office Web Apps Server 2013 and WebReady document viewing, the risk of security flaws alone may make Office Web Apps Server more compelling, not to mention that it also offers better document fidelity. But if you're upgrading from Exchange 2007 or 2010, the flaws in WebReady document viewing are already present in your environment; using Exchange 2013 with WebReady document viewing won't necessarily make things worse.
Office Web Apps Server 2013 is great if you're installing multiple Office 2013 Server products. But if you're only installing Exchange 2013 in a smaller organization, don't forget WebReady document viewing is still included and provides similar functionality.
About the author:
Steve Goodman is an Exchange MVP and works as a technical architect for one of the U.K.'s leading Microsoft Gold partners. Goodman has worked extensively with Microsoft Exchange since version 5.5 and Office 365 since its origins in Exchange Labs and Live@EDU.